It is known that bodywork parts that are painted off the main assembly line for a vehicle need to be painted in compliance with precise criteria in terms of color and surface state so that said parts present the same appearance as the remainder of the bodywork which is painted as a whole.
It is also known that the settings of a painting line can drift as a function of various factors, such as, for example: humidity, ambient temperature, and atmospheric pressure, and that it is essential to monitor parts on leaving the painting line, at least to inspect their quality, and possibly also to adjust the settings of the painting line accordingly.
To this end, it is known to use an optical measuring instrument such as that sold under the reference Carflash by the American supplier X-Rite.
That instrument is installed at the end of a painting line on a stop-and-go station, i.e. a station in front of which parts under inspection are stopped, with measurements being performed while they are stationary, after which they continue moving along the line.
Until now, stations for inspecting the painting of motor vehicle bodywork parts have always been of the stop-and-go type since the measurement instrument is known to be highly sensitive to vibration, and any movement of parts along the line inevitably leads to high levels of vibration in the parts.
Indeed, the manufacturer recommends that the measurement instrument be used in that way.
Their drawback is particularly severe insofar as it applies to painting lines in which bodywork parts are carried individually by trays or masts, moving on a conveyor, and their low weight does not give them sufficient inertia to absorb vibration from the conveyor.
Things are different on a line for painting unpainted “bodies-in-white” of vehicles, since they are heavy enough to limit considerably the effects of conveyor vibration.